composite developments for lightweighting heavy …...8/12 composite developments and opportunities...
TRANSCRIPT
Composite Developments for Lightweighting Heavy Duty Vehicles
Rhys Tapper 12-Nov-14
www.bris.ac.uk/composites
2/12Lightweighting Incentives: Regulations
Fuel emission regulations• The US DOE mandated a 50 % improvement in freight efficiency for
heavy duty vehicles (HDVs).
• DOE stated a 50 % reduction in green house gas emissions by 2030.
Lightweighting• 6-8 % increase in fuel economy can be achieved by a 10 % weight
reduction.
• Fuel is the single largest expense for fleet owners, ~50 % of a HDVs total operating cost.
• Increased payload as fleet owners are reported as working within tight (2-4 %) profit margins.
Lightweighting Heavy Duty Vehicles
3/12Lightweighting Incentives: Composite Materials
Composite Materials• Superior specific strength is the main impact factor for composite
usage.
• Significant advantages over traditional materials include;– Corrosion, scratch and dent resistance. – Reduced noise vibration harshness.– High specific energy absorption.– Increased design flexibility.– Reduced tooling costs.– Dimensional stability.
Lightweighting Heavy Duty Vehicles
4/12Heavy Duty Vehicles: Classifications
Lightweighting Heavy Duty Vehicles
• There are two main elements, the tractor unit and trailer unit, the latter is mounted directly onto the chassis frame.
• HDV’s and SUV’s represent 93 % of the fuel used by all US trucks.
• They can cover between 150,000 and 200,000 miles a year.
• Average fuel consumption for new HDV’s is ~ 6 mpg, this needs meet 10 mpg.
US DOE; R&D opportunities report; 2009
US DOE; Workshop report; 2013
5/12Heavy Duty Vehicles: Classifications
Lightweighting Heavy Duty Vehicles
• The tractor unit, empty trailer and payload represent approximately 16 %, 20 % and 64 % of the GVWR (36,300 kgs) respectively.
• Main load-bearing elements are heavy steel-girder frame assemblies.
• US and EU/UK model powertrain orientation can differ due to size restrictions.
US DOE; Energy, materials and vehicle weight reduction; 2009
6/12Composite Developments and Opportunities
Lightweighting Heavy Duty Vehicles
Cab unit – 18 % of tractor weight• Compression moulded SMC is currently the most common composite
process used in truck part mass-manufacture. Injection moulded methods are less widely used.
• SMC is usually made using cheap thermoset resins and discontinuous glass fibres.
• SMC is the most cost-effective for moderate production volumes, offers agreeable cycle times and automotive grade quality and finishes.
Fairings
Cab interior/exterior
components
Trims
Doors
Bumpers
Grill panel
• Part production volume for HDVs averages 5,000 and 20,000 parts per year, for cars it can be between 80,000 and 500,000 per year.
7/12Composite Developments and Opportunities
Lightweighting Heavy Duty Vehicles
Powertrain – 48 % of Tractor weight• Engines always cast from iron/steel.
• HDV drivetrain components are subjected to high stresses, i.e. torsional for driveshafts, composite materials must be able to withstand these.
• A CFRP driveshaft has been made by filament winding for LDVs.
• Inadequate manufacturing capacity for these components
• Lightweight materials that can withstand the high-demand of HDV propulsion systems are not cost competitive.
www.ifc-composite.com
8/12Composite Developments and Opportunities
Lightweighting Heavy Duty Vehicles
Chassis & suspension – 31 % Tractor weight• Steel frames sometimes with wooden cross
members - leads to major corrosion and rottingissues.
• Steel truck chassis claiming to offer 30 % weight reduction.
• FRP leaf and coil springs are used in LDVs and CFRP compression rings.
• Inadequate material properties to withstand part environment.
• Manufacturing capacity to produce these components is lacking.
www.ifc-composite.com
www.articles.sae.org/11850
Hawkins; Composite multi-wave compression spring; 6068250; 2000
9/12Composite Developments and Opportunities
Lightweighting Heavy Duty Vehicles
Trailer – Box or Flat-bed• Floor is usually wooden decking laid into a steel
frame. Stiff, cheap, durable material that can be replaced easily.
• Walls are sheet metal with plywood backing –rotting issues. UK/EU trailers can have curtain sides attached by metal fasteners/rails.
• Sandwich panels are available for trailer wall panels and aerodynamic skirts. CF panels should be considered for trailer beds.
• Trailer life time 3 x that of tractors and sales have dropped 72 % since 2009 - new technologies could be slow to return investment costs.
10/12Composite Developments and Opportunities
Lightweighting Heavy Duty Vehicles
• The DOE, under the ‘SuperTruck’ project, has previously funded OEM’s and vehicle manufacturer collaborations to help stimulate composite growth.
US DOE; Energy efficiency and
renewable energy; 2010
11/12Technological Barriers
Lightweighting Heavy Duty Vehicles
Cost• GF remain the most competitive but CF and metal alloys are far too
expensive – manufacturing and precursor alternatives.Manufacture• Part production volume is moderate but capacity for lightweight
components is lacking.Modelling• Lack of design tools, design data and adequate testing methods. High-
fidelity computation modelling for micro/meso/macro is needed for composites which is expensive.
Joining, Repair and Detection• Lack of robust, cost-effective methods for joining composites especially for
load-bearing applications. Detection of damage is difficult for large composite pieces. Policy of ‘replace’ – modular design - could be necessary whilst technology develops.
12/12Heavy Duty Vehicles Aren’t That Boring!
Lightweighting Heavy Duty Vehicles
Thank you for your attention at the end of a long day of presentations
Any Questions?